Damping top, damping rod, and damping device using same

ABSTRACT

A damping top which comprises first and second L1 connection members (10, 20) connected to each other so as to connect two relatively displacing points (objects) (L1, L2) to each other, which connection members are fixed at one end thereof to the two points (L1, L2), respectively. The first connection member (10) is formed at its connection side with a guide screw portion (10a), on which is rotatably and slidably mounted a rotating top (integral rotating unit) (16) adapted to be driven by a guide nut (14) threaded onto the screw portion through a ball bearing (12). The second connection member (20) is formed at its connection side in a casing (24) for a chamber (22), which receives therein the rotating top (16), and a damping viscous body (26) is filled in the chamber (22). Thus it is possible to provide a damping device which is simple and small-sized, and provides great damping effects.

TECHNICAL FIELD

The present invention relates to a damping top (damping mechanism), adamping rod and damping devices using the same which have simplestructures and small sizes and also are capable of providing greatdamping effects.

BACKGROUND OF THE ART

In general, the damping mechanism is provided between two points(objects) relatively displacing to each other, so that a vibrationenergy to be transferred from one vibration source side to other dampingobject side is converted into a thermal energy for causing the vibrationenergy to disappear, thereby achieving the damping effects.

The above mentioned damping mechanism is so structured that partsrelatively displacing to each other by vibration are accommodated in achamber including a viscous material, which is formed in the device,whereby the damping effect is achieved through its viscous andfrictional resistance, and further in this case so structured that anamount of displacement of the above mentioned relatively displacingparts is amplified by an amplification means from an actual displacementamount (a displacement amount of two points relatively displacing),whereby the damping effect is thus increased. By the way, the dampingeffect is proportional to a confronting area to the first power betweenthe two parts relatively displacing (operating to each other) and alsoto a relative speed to alpha power.

The above mentioned conventional damping mechanism, however, hasdifficulties to be described below. As described above, the conventionaldamping mechanism, in general, has means for amplifying the relativelydisplacing parts, wherein this displacement amplifying means normallycomprises a leverage means connected thereto by a hinge-joint. Such thehinge-leverage means is, however, insufficient in amplifyingmagnification (rate in increase of the confronting area of therelatively displacing parts and the relative speed between them) andalso is complicated in structure, whereby the structure is enlarged andaccuracy in operation is also dropped.

Accordingly, an object of the present invention is to provide adisplacement-amplifying means having a simple and compact structure andbeing capable of achieving a large amplifying magnification, namelyprovide a damping device having a simple and compact structure and beingcapable of achieving a large damping effect.

DISCLOSURE OF THE INVENTION

In order to achieve the above object, a first damping device (dampingtop) in accordance with the present invention comprises: first andsecond connective members so connected with each other as to berelatively displaceable ; the first connective member further comprisinga first rod formed with a guide screw in its connecting side, a guidenut engaged with the guide screw and axially supported so as to rotateand slide on the guide screw on the basis of a relative displacementfrom the guide screw, and a disk-shaped rotational body having asufficiently larger diameter than the first rod and being rotatably andslidably attached thereto through the guide nut; the second connectivemember further comprising a second rod, and a cylindrically shapedcasing formed in its connecting side for accommodating the rotationalbody and the guide nut, and the damping device is characterized in thata viscous material and/or a viscoelastic material is filled for dampingin a gap defined between an inner wall of the cylindrically shapedcasing and the rotational body.

The rotational body may so unitary be formed as to extend radially andoutwardly from a circumference of the guide nut, or may be provided at aposition distanced in an axial direction from the guide nut and also isso formed as to be engaged with one side of the guide nut.

The damping device may be provided between diagonally opposite comers ofa frame structure in a building construction, or may be provided betweenprecast members and/or fair-faced constructions in a fair-faced buildingconstruction including precasts of concrete, or may be provided betweena foundation of a building construction and a fair-faced floor slab,wherein the damping device connects isolated floors through a precaststeel extending throughout the isolated floors and also extending alongan outermost vertical column of the building which consisting of aplurality of floors.

The second damping device in accordance with the present inventioncomprises: first and second connective members so connected with eachother as to be relatively displaceable; the first connective memberfurther comprising an inner tube formed with a guide screw in itsconnecting side, and a disk-shaped rotational body engaged with theguide screw and having a sufficiently larger diameter than the innertube and being attached thereto rotatably and slidably on the basis of arelative displacement from the guide screw; the second connective memberfurther comprising an outer tube, and a cylindrically shaped casingformed in its connecting side for accommodating the rotational body, andthe damping device is characterized in that a viscous material and/or aviscoelastic material is filled for damping in a gap defined between aninner wall of the cylindrically shaped casing and the rotational body.

The rotational body may preferably comprise a disk-shaped body and abrimmed part being thinner than the disk-shaped body and extendingradially and outwardly from a circumference of the disk-shaped body. Thedamping device may preferably be so provided as to connect isolatedfloors through a precast steel extending throughout the isolated floorsand also extending along an outermost vertical column of the buildingwhich consisting of a plurality of floors.

A damping rod in accordance with the present invention may comprise;first and second connective members so connected with each other as tobe relatively displaceable; the first connective member furthercomprising a first rod formed with a guide screw at least in itsconnecting side, a guide nut engaged with the guide screw and axiallysupported so as to rotate and slide on the guide screw on the basis of arelative displacement from the guide screw, and a cylindrically shapedrotational body having a sufficiently larger diameter than the first rodand having a sufficiently larger length in anal direction than adiameter itself and further being rotatably and slidably attachedthereto through the guide nut; the second connective member furthercomprising a cylindrically shaped casing formed in its connecting sidefor accommodating the cylindrically shaped rotational body and the guidenut, and the damping device is characterized in that a viscous materialand/or a viscoelastic material is filled for damping in a gap definedbetween an inner wall of the cylindrically shaped casing and thecylindrically shaped rotational body.

In this case, the cylindrically shaped rotational body may comprise acylinder having one end into which the guide nut is inserted and anopposite closed end, wherein one side of the guide nut and the oppositeclosed end of the are rotatably and axially supported. The cylindricallyshaped rotational body may also comprise a tube-like rotational bodyhaving one end into which the guide nut is inserted and an oppositeopened end, wherein opposite sides of the guide nut are rotatably andaxially supported and further the viscous material and/or theviscoelastic material is also filled into a hollow portion of thetube-like rotational body.

The damping device may be provided between diagonally opposite cornersof a frame structure in a building construction, so that the dampingdevice is allowed to be compressed and tensed, or may be providedbetween a foundation and a vibration-isolating construction on thefoundation, so that the damping device is allowed to be compressed andtensed.

In the first damping device in accordance with the present invention,the displacement amplifying means comprises a rotational body or arotational top driven or rotated slidably by the guide nut engaged withthe guide screw of the first connective member, for which reason therelative speed increasing rate, “N” is given by the following equation.

N=2πr/p

where “p” is the pitch of the nut and the guide screw, and “r” is therepresentative radius of thc rotational top, whereby the relative speedincreasing rate “N” is selected sufficiently large by setting propervalues for “p” and “r”. Assuming that “p” and “r” are set 2 cm and 5 cmrespectively, “N” is amplified by 15.7 times. In this case, if thedamping top is used to the bracing, then “N” is further amplified by22.2 times. The confronting area “A” is also selected sufficiently largeby setting proper values for “p” and “r”. The effect of the abovedamping top provided by those will be described in the embodiments asmentioned below. This displacement amplification means comprises thescrew-nut mechanism which may be simple and compact-size.

The damping device using the second damping top in accordance with thepresent invention has superior characteristics and may be structuredsimply and compactly and also may exhibit sufficient damping effect,similarly to the above first damping top. Accordingly, the first andsecond damping devices in accordance with the present invention have thesimple and compact structure and are capable of exhibit large dampingeffects.

In the damping device (damping rod) in accordance with the presentinvention, the displacement amplifying means comprises a rotationalinner cylinder driven or rotated slidably by the guide nut engaged withthe guide screw of the first connective member, for which reason therelative speed increasing rate “N” is given by the following equation.

N=πD/p

where “p” is the pitch of the nut and the guide screw, and “D” is thediameter of the rotational inner cylinder, whereby the relative speedincreasing rate “N” is selected sufficently large by setting propervalues for “p” and “D”. Assuming that “p” and “D” are set 2 cm and 10 cmrespectively, “N” is amplified by 15.7 times. In this case, if thedamping top is used to the bracing, then “N” is further amplified by22.2 times. The confronting area “A” is also selected sufficiently largeby setting proper values for the above diameter “D” and a length “L” ofthe rotational inner cylinder. The effect of the above damping rodprovided by those will be described in the embodiments as mentionedbelow. This displacement amplification means comprises the screw-nutmechanism which may be simple and compact-size. Namely, the dampingdevice in accordance with the present invention have the simple andcompact structure and are capable of exhibit large damping effects.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a cross sectional view illustrative of a damping device havinga damping top in one embodiment in accordance with the presentinvention,

FIG. 2 is a cross sectional view illustrative of a damping device havinga damping top in a first modification in accordance with the presentinvention.

FIG. 3 is a cross sectional view illustrative of a damping device havinga damping top in a second modification in accordance with the presentinvention.

FIG. 4 is a side view illustrative of a damping device having a dampingtop with one structure in accordance with the present invention.

FIG. 5 is a side view illustrative of a damping device having a dampingtop with another structure in accordance with the present invention.

FIG. 6 is a side view illustrative of a damping device having a dampingtop with further another structure in accordance with the presentinvention.

FIG. 7 is a whole sectional view illustrative of a buildingconstruction, wherein a damping device in accordance with the presentinvention is applied between diagonally opposite corners of the framestructure of the building construction.

FIG. 8 is an enlarged view at an “A” portion of FIG. 7.

FIG. 9 is an enlarged view at a “B” portion of FIG. 7.

FIG. 10 is a whole sectional view illustrative of a fair-facedconstruction, wherein a damping device in accordance with the presentinvention is applied at sites 70 a, 70 b, 70 c and 70 d between precastmembers of the concrete and/or the fair-faced construction.

FIG. 11 is a perspective view illustrative of a damping device using adamping top applied to the site 70 a in FIG. 10.

FIG. 12 is a cross sectional view taken along a VII—VII line of FIG. 11.

FIG. 13 is a cross sectional view illustrative of a damping device usinga damping top applied to the site 70 b in FIG. 10.

FIG. 14 is a cross sectional view illustrative of a damping device usinga damping top applied to the site 70 c in FIG. 10.

FIG. 15 is a cross sectional view illustrative of a damping device usinga damping top applied to the site 70 d in FIG. 10.

FIG. 16 is a whole cross sectional view of illustrative of a foundationand a vibration isolation construction, wherein a damping device inaccordance with the present invention is applied between the foundationand the vibration isolation construction over this foundation.

FIG. 17 is a schematic view, wherein a damping top in accordance withthe present invention is placed on the foundation to support thebuilding construction.

FIG. 18 is a schematic view, wherein a damping top in accordance withthe present invention is placed to suppress a bending deformation of ahigh-rise building construction on the foundation to support thebuilding construction.

FIG. 19 is a cross sectional view illustrative of a damping device(damping rod) in one embodiment in accordance with the presentinvention.

FIG. 20 is a cross sectional view illustrative of a damping device(damping rod) in another embodiment in accordance with the presentinvention.

FIG. 21 whole sectional view illustrative of a building construction,wherein a damping device (damping rod) in accordance with the presentinvention is applied between diagonally opposite corners of the framestructure of the building construction.

FIG. 22 is an enlarged view at an “A” portion of FIG. 21.

FIG. 23 is an enlarged view at a “B” portion of FIG. 21.

FIG. 24 is a whole perspective view of illustrative of a foundation anda vibration isolation construction, wherein a damping device inaccordance with the present invention is used between the foundation andthe vibration isolation construction over this foundation.

FIG. 25 is a schematic view of illustrative of a damping rod erectedbetween two points in the building construction.

FIG. 26 is a fragmentary cross sectional view in FIG. 25.

BEST MODES FOR CARRYING OUT THE INVENTION

The damping top of the first embodiment in accordance with the presentinvention will hereinafter be described with reverence to the attacheddrawings. In FIG. 1, the damping device in accordance with the presentinvention may basically comprise first and second connective members socoupled with each other as to connect two points (objects) L1 and 12relatively displacing from one another. Namely, the damping devicecomprises a first rod 10 and a tube-shaped second rod 20. Those rods 10and 20 are connected through those ends to the two points L1 and L2respectively. The first rod 10 has a connective part formed of a screwportion 10 a to which a guide nut 14 is engaged through ball bearings12, and a rotational top 16 is attached to the guide nut 14 so that therotational top 16 is rotatable and slideable over the screw portion 10a. The second rod 20 is formed in its connecting side with a casing 24defining a chamber 22 which accommodates the above rotational top 16, sothat a damping viscous material and/or viscoelastic material 26 isfilled in this chamber 22.

The guide nut 14 is provided with ball bearings 28 and 30 on its top andbottom faces adjacent to the casing 24 which surrounds the guide nut 14,whereby the guide nut 14 is axially supported so as to rotate on theguide screw portion 10 a and slides in top and down directions inresponse to both compressive and tensile loads generated by a relativedisplacement between the two points L1 and L2. The rotational top 16comprises a unitary rotor 16 extending outwardly in radial directionsfrom a circumference of the guide nut 14. Synthesized rubbers such aspolyisobutylene way preferably be used as viscous fluid.

The damping effect of the damping device in accordance with the presentinvention will be described in detail. The damping top 50 is placed on afoundation 71 to support a building construction 70 (in FIG. 17).

Predominant (fundamental) frequency of the building construction: n (Hz)

Deformation (maximum) in axial direction of the damping (damping) top50: d (cm)

Screw pitch of the guide screw and the nut 52: p (cm)

Rotation in a half-period Δt(=½n): m=d/p

Rotational frequency (per 1 sec.) of the rotational top 56: f=2dn/p

Diameter (radius) of the rotational top 56: D (radius R=D/2)

Area of the rotational top 56: top face

; Atop=π(D²−D0²)/4

; Abottom=90 (D²−D0²)/4

; Atotal=πD²/4(D⁰is ignored)

Angular rateω(rad./sec.) of the rotational top 56 is given by thefollowing equation (1).

ω=2πf=4πdn/p  (1)

Representative velocity v(m/sec) of the rotational top 56 is given by;

V=2πfr=4dnr/p (r is the representative radius)

Assuming that r=⅔R (=D/3), “v” is represented by the following equation(2).

V=4πdnD/3p  (2)

In such the damping top, the damping force Qd (kg) of the viscousmaterial is generally given by the following equation (3).

Qd=aμ(dv/dy)^(α) A  (3)

where

“a”: coefficient

“μ”: viscosity of the viscous material (kg sec/cm²)

“dv”: difference in velocity between two faces (inner face of thechamber 54 and surface of the rotational top 56)

“dy”: gap (cm) between two faces (inner face of the chamber 54 andswrace of the rotational top 56)

“A”: confronting area between two faces (inner face of the chamber 54and surface of the rotational top 56).

The damping force per a unit gap (1 cm) is calculated from the followingequation (4) which is obtained by incorporating the equation (2) intothe equation (3).

Qd=a μA(4πdnD/3p)^(α) πD ²/2  (4)

As an experimental result, the following approximated values have beenobtained.

“a”: 0.0843 (μ30)^(−0.483)(μ30 is the viscosity of the viscous materialat a temperature of 30° C.).

“μ”: 7.1(μ30)^(0.88) e ^(−0.07t) (t is the temperature)

“α”: 0.94

As the simplified relational equation, the following equation (5) hasbeen obtained.

Qd=0.6f ^({1.17(μ30)0.3})(μ30)^(0.4) ×e ^(−0.7t) A(v/dy)^(0.94)  (5)

From the above equations (1) and (2), the following relationships areobtained.

A=πD²/2

V=4πdnD/3p

Assuming that:

n=1.0 Hz;

d=5 cm;

p=0.5 cm;

D=40 cm;

dy=1 cm, then

f=2dn/p=2 5 1/0.5=20(rps);

A=πD²/2=about 2500 (cm²);

V=4πdnD/3p=4π5 1 40/3 0.5=1670 (cm/sec); and

for the used viscous material, μ30=100 poise=1/9.8×10³ (kg sec/cm²), theabove damping force Qd is calculated from the above equation (5) asfollows.

Qd=0.6×20^({−1.17(1/9800)0.3})(1/9.8×10³)^(0.4) ×e ^(−0.07×20)A(v/dy)0.94

=0.6×0.8×0.253×0.2466×2500×(1670)^(0.94)

=8010 (kg)

Such the damping top uses the small flat rotational top 56 of 40 cm indiameter to obtain a large damping force of about 8 tons.

The damping top in accordance with the present invention has such asimple and compact structure as to convert a linear displacement of thescrew portion into a rotational motion of the rotational top and whichis shortened in a longitudinal direction, and an extremely large dampingeffect can easily be achieved as compared to the conventional device.Further, it is advantageous that this damping top is applied to arelatively large building and also to a small prefabricated structure,as well as applicable to both compressive and tensile loads.

The above damping top in accordance with the present invention mayvariously be modified, for example, as shown in FIG. 2. The firstconnective member is changed from the tube rod 20 into a normal rod 40.The rotational top is also changed from the unitary formed rotor 16 intoa separate rotor 42 extending in parallel to a radial direction andseparated from one side of the guide nut 14. The separate rotor 42 isaccommodated in a chamber 22 in a first casing formed in a connectiveside of the rod 40 (the second connective member). The guide nut 14 isaxially supported through ball bearings 28 and 30 in a second casing 44.It is apparent that in this modification, the same functions and effectsas the above embodiment are exhibited.

As a further modification in FIG. 3, the damping device comprises firstand second connective members so connected to each other as to berelatively displaceable from each other. This first connective membercomprises an inner tube 100 formed with a guide screw 102 in itsconnective side, and a disk-shaped rotor engaged with this screw andhaving a sufficiently larger diameter than the inner tube I00 as well asprovided rotatably and slidably on the guide screw in accordance with arelative displacement from the screw 102. The rotor 104 comprises adisk-shaped body 104 a and a brimmed portion 104 b extending radiallyfrom a circumference of the disk-shaped body 104 a and being formedthinner than the disk-shaped body 104 a. The second connective membercomprises an outer tube 110 and a cylindrically shaped casing 112 formedin its connective side for accommodating the rotor 104. Further, therotor 104 is so supported rotatably and slidably through plural ballbearings 116 A viscous material and/or viscoelastic material 114 fordamping is filled into the gap between the inner wall of thecylindrically shaped casing 112 and the rotor 104. It is also apparentthat in this modification, the same function and effect as the aboveembodiment can be exhibited.

The damping top in accordance with the present invention is as describedabove widely applied to a large building and a small prefabricatedstructure, for which reason a whole stricture may be optional inresponse to the usage. In the damping top shown in FIG. 4, the oneconnective member 50 b comprises a longitudinal connective member 50 b.In the damping device 50 shown in FIG. 5, te one connective member 50 bis connected with an extending member 50 c. In the damping device 50shown in FIG. 6, the one connective member 50 a comprises an insertingconnective member 50 a and other connective member 50 b is heldrotatably in a holding portion d.

The embodiment of the damping device using the damping top having suchstructure in accordance with the present invention, particularly theembodiment for application to the building construction, willhereinafter be described in detail. In FIG. 7, the damping device shownin FIG. 4 is used. The damping top 50 is provided through connectingmembers 50 a and 50 b and also through an extension member 50 c betweenattached plates 72 a and 72 b at diagonally opposite comers of a framestructure 72 in a building construction 70 so that the damping top 50 isallowed to be compressed and tensed. Accordingly, the damping effect bythe damping top 50 expandable by a displacement due to strain to theframe structure 74 generated by earthquakes does absorb a strain energyof the frame structure 74, whereby an effective damping to the vibrationof the building construction 70 can be obtained

In FIG. 10, the damping tops 50 may be provided so as allowed to becompressed and tensed individual sites 70 a, 70 b, 70 c and 70 d (to bedescribed below individually) between precasts and/or fair-facedstructure in the fair-faced construction including precast members ofconcrete. In FIGS. 11 and 12 relating to the site 70, the damping top 50is provided in a filler 78 between a precast column 74 and a precastbeam 76. End portions of the connective members 50 a and 50 bindividually penetrating through both the above members 50 a and 50 b(loosely engaged in at least one side 50 b) are engaged by nuts with endportions of the both members 50 a and 50 b. Accordingly, the dampingeffect by the damping top 50 expandable due to relative displacementbetween the both members 50 a and 50 b generated by earthquakes doesabsorb a relative displacement energy of the both members 50 a and 50 b,whereby an effective damping to the vibration of the buildingconstruction 70 can be obtained.

In FIG. 13 relative to the site 70 b, the damping top 50 shown in FIG. 5is used. This damping top is provided between a precast column 74 and afair-faced construction 80. The one side connective member 50 a isburied in the column 74 whilst the other connective member 50 b isrotatably held by a holder 50 d fixed to a floor 80. Accordingly, thedamping effect by the damping top 50 expandable through extension andrestoration due to relative displacement between the column 74 and thefloor 80 generated by earthquakes does absorb a relative displacementenergy of the column 74 and the floor 80, whereby an effective dampingto the vibration of the building construction 70 can be obtained.

In FIG. 14 relative to the site 70 c, the damping top 50 includingprecast connective members 50 b and 50 a is entirely fixed through aholder 50 d into a fair-faced construction 80. The top of the one sideconnective member 50 a is connected with a supporter 82 and alsoconnected through both supporting rods 84 a and 84 b to predeterminedsites of the floor 80. Accordingly, the damping effect by the dampingtop 50 expandable through extension and restoration due to relativedisplacement the floor 80 itself generated by earthquakes does absorb arelative displacement energy of the floor 80, whereby an effectivedamping to the vibration of the building construction 70 can beobtained.

FIG. 15 relative to the site 70 d, the damping top 50 is providedbetween a foundation 86 and a fair-faced construction 80 through aholder 50 d over a building construction foundation 86, and its bothconnective members 50 b and 50 a arc connected to predeterminedpositions L1 and L2 respectively in the floor 80. Accordingly, thedamping effect by the damping top 50 expandable due to a relativedisplacement in horizontal direction between the foundation 86 and thefloor 80 generated by earthquakes does absorb a relative displacementenergy in horizontal direction between the foundation 86 and the floor80, whereby an effective damping to the vibration of the buildingconstruction 70 can be obtained.

In FIG. 16, the damping top 50 is provided through supporting columns 86a and 90 a between a foundation 86 and a vibration isolationconstruction 90 supported through aseismic base isolation pads 88 overthe foundation 86, so that the damping top 50 is allowed to becompressed and tensed. Accordingly, the damping effect by the dampingtop 50 expandable due to a relative displacement in horizontal directionbetween the foundation 86 and the vibration isolation construction 90generated by earthquakes does absorb a relative displacement energy inhorizontal direction between the foundation 86 and the vibrationisolation construction 90, whereby an effective damping to the vibrationof the building construction 70 can be obtained.

As shown in FIG. 18, the damping top may be used for a dampingconstruction method to bending deformation 64 of the high-rise buildingor the super high-rise building. For the high-rise building or the superhigh-rise building, the bending deformation is more important than sheardeformation. In order to suppress this bending deformation, it isnecessary to improve a bending deformation damping property of columnsextending in a vertical direction of the building. It is, however,difficult to suppress vertical micro-fluctuations, for which reason itis necessary to increase the vertical microflucttiation for suppressingthe bending deformation. For example, as illustrated in FIG. 18,isolated floors of the high-rise building or the super high-risebuilding are connected through slender members such as precast (PC)steel wires 60 or PC steel in combination with the damping top inaccordance with the present invention, so as to increase the verticalmicro-fluctuation for suppressing the bending deformation. The slendermember such as the PC steel wires as the connective members is moreeffective to the tension. It is preferable to place the above device inthe vicinity of the outermost vertical columns of the building, but itis also possible to provide the same at an interior of the building oran exterior of the building or within the columns. The above device maybe provided to connect floors isolated by two or three floors. In abuilding structure, the device may bc provided to connect the highestfloor and the ground.

The damping rod of the first embodiment in accordance with the presentinvention will hereinafter be described with reverence to the attacheddrawings. In FIG. 19, the damping rod 160 in accordance with the presentinvention comprises first and second connective members 160 and 130 socoupled with each other as to connect two points (objects) L1 and L2relatively displacing from one another. The individual ends of the bothconnective members 120 and 130 are fixed to the two points L1 and L2respectively. The first connective member 120 has a connective partformed of a screw portion 120 a on which a rotational inner cylinder 126driven by a guide nut 124 engaged through ball bearings 122 thereto isrotatably and slidably provided. The second connective member 130 is inthe form of a fixed outer cylinder 134 for a chamber 132 accommodatingthe rotational inner cylinder 126, so that a damping viscous materialand/or viscoelastic material 26 is filled in this chamber 132.

The rotational inner cylinder 126 comprises a cylinder having one endengaged with the guide nut 124 and opposite end being closed. Ballbearings 138 and 140 are provided on both top face of the guide nut 134and bottom face of the closing end of the rotational inner cylinder 126adjacent to the fixed outer cylinder 134, whereby the rotational innercylinder 126 is axially supported so as to rotate on the guide screwportion 120 a and slides in top and down directions in response to bothcompressive and tensile loads generated by a relative displacementbetween the two points Li and L2. Synthesized rubbers such aspolyisobutylene may preferably be used as viscous fluid.

The damping effect of the damping device in accordance with the presentinvention will be described in detail. The damping device 160 is placedbetween two points Li and 12 of the building construction 70 (in FIGS.25-26).

Predominant (fundamental) frequency of the building construction: n (Hz)

Deformation (maximum) in axial direction of the damping (damping) rod160: d (nm)

Screw pitch of the guide screw and the nut 162; p (cm)

Rotation in a half-period Δt(=½n): m=d/p

Rotational frequency (per 1 sec.) of the rotational inner cylinder 166;f=2dn/p

Diameter (radius) of the rotational inner cylinder 166: D

Length of the rotational inner cylinder 166: L

Surface area of the rotational inner cylinder 166 : A=πDL

Angular rateω(rad./sec.) of the rotational inner cylinder 166 is givenby the following equation (1).

ω=2nf=4πdn/p  (1)

Circumferential velocity v(m/sec) of the rotational inner cylinder 166is given by:

V=2πdnD/p  (2)

In such the damping device, the damping force Qd (kg) of the viscousmaterial is generally given by the following equation (3).

Qd=aμ(dv/dy)^(α) A  (3)

where

“a”: coefficient

“μ”: viscosity of the viscous material (kg sec/cm²)

“dv”: difference in velocity between two faces (inner face of the fixedouter cylinder 166 and outer face of the rotational inner cylinder 164)

“dy”: gap (cm) between two faces (inner face of the fixed outer cylinder166 and outer face of the rotational inner cylinder 164)

“A”: confronting area between two faces (inner face of the fixed outercylinder 166 and outer face of the rotational inner cylinder 164).

The damping force per a unit gap (1 cm) is calculated from the followingequation (4) which is obtained by incorporating the equation (2) intothe equation (3).

Qd=aμA(4πdnD/p)^(α)  (4)

As an experimental result, the following approximated values have beenobtained.

“a”: 0.0843(μ30)^(−0.483)(μ30 is the viscosity of the viscous materialat a temperature of 30° C.).

“μ”: 7.1(μ30)^(0.88) e ^(−0.07t)(t is the temperature)

“α”: 0.94

As the simplified relational equation, the following equation (5) hasbeen obtained.

Qd=0.6f ^({−1.17(μ30)0.3})(μ30)^(0.4) ×e ^(−0.07t) A(v/dy)^(0.94)  (5)

From the above equations (1) and (2), the following relationships areobtained.

Assuming that:

n=1.0 Hz;

d=5 cm;

p=0 cm;

D=40 cm;

dy=1 cm;

μ30=100 poise 1/(9.8×10³)(kg sec/cm²); and

t=20(° C.), then

f=2dn/p=2×5×1/0.5=20(rps);

A=πDL=π×10×100=3142(cm²);

V=2πdnD/p=2×π5×1×10/0.5=628 (cm/sec); and

the above damping force Qd is calculated from the above equation (5) asfollows.

Qd=0.6×20^({−1.17(1/9800)0.3})(1/9800)^(0.4) ×e^(−0.07×20)×3142×(628/1)^(0.94)

=0.6×0.8×0.0253×0.2466×3142×(328)^(0.94)

=2180(kg)

Such the damping devicc uses the rotational inner slender cylinder 166of 10 cm in diameter and 100 cm in length to obtain a large dampingforce of about 2.2 tons.

Assuming only a linear displacement, and if the velocity v′ (cm/sec) ofthe rotational inner cylinder 166 is given by

V′=d/2n=5/2 1=2.5(cm/sec), then

the above damping force Qd is calculated similarly to the above equation(5) as follows.

Qd′=0.6×1×(1/9800)^(0.4) ×e ^(−0.07×20)×3142×(2.5)^(0.94)

=0.6×0.0253×0.2466×3142×2.4

=27.8 (kg)

As compared to the above damping force Qd, the above damping force isabout 78 times of this damping force Qd′ if the liner displacement onlyappears.

In accordance with the present invention, the damping device has asimple and compact structure for converting the liner displacement ofthe screw portion into the rotational motion of the rotational innercylinder (particularly extending along the longitudinal direction), andan extremely large damping effect can easily be achieved as compared tothe conventional device. Further, it is advantageous that this dampingdevice is applied to a relatively large building and also to a smallprefabricated structure, as well as applicable to both compressive andtensile loads.

The above damping device in accordance with the present invention mayvariously be modified, for example, as shown in FIG. 20. In thismodification to the embodiment of FIG. 19, the rotational inner cylinder126 is in the form of opening cylinder and also the guide nut 124 isaxially supported through ball bearings 138 and 140 to the casing 142fixed to the fixed outer cylinder 134. It is apparent that, in thisembodiment, also the same functions and effects as in the aboveembodiment are exhibited. As also described above, the above dampingdevice of the present invention, is applied to a relatively largebuilding and also to a smalI prefabricated structure.

The embodiment of the damping device using the damping rod in accordancewith the present invention will hereinafter be described in detail. InFIG. 21, the damping rod 160 is provided through connecting members 170a and 170 b and also through connecting members 160 a and 160 b atdiagonally opposite comers of a frame structure 174 in a buildingconstruction 172 so that the damping rod 160 is allowed to be compressedand tensed. Accordingly, the damping effect by the damping rod 160expandable by a strain displacement due to strain to the frame structure74 generated by earthquakes does absorb a strain energy of the framestructure 174, whereby an effective damping to the vibration of thebuilding construction 172 can be obtained.

In FIG. 24, the damping device 160 is provided through supportingcolumns 176 a and 180 a between a foundation 176 and a vibrationisolation construction 180 supported through aseismic base isolationpads 178, 178 over the foundation 176, so that the damping device 160 isallowed to be compressed and tensed. Accordingly, the damping effect bythe damping device 160 expandable due to a relative displacement inhorizontal direction between the foundation 176 and the vibrationisolation construction 180 generated by earthquakes does absorb arelative displacement energy in horizontal direction between thefoundation 86 and the vibration isolation construction 80, whereby aneffective damping to the vibration of the building construction 80 canbe obtained. In accordance with the damping devices of the presentinvention, the damping top and the damping rod are simply and compactlystructured and exhibit sufficiently large damping effects.

Whereas preferred embodiments of the present invention have beendescribed, it is possible to do many improvements and modificationswhich fall within the spirit and scope of the present invention withoutlimitation to the above embodiments. For example, it is possible tochange the ball bearings into other supporting means optionally

Industrial Applicability

As described above, a damping top in accordance with the presentinvention comprises first and second connective members so connectedwith each other as to be relatively displaceable, and individual oneends of the connective members are fixed to the above two pointsrespectively, and the first connective member is formed with a guidescrew in its connecting side, a guide nut engaged with said guide screwand axially supported, whilst the second connective member further isformed of a cylindrically shaped casing in its connecting side foraccommodating the rotational top, and a viscous material and/or aviscoelastic material is filled in the chamber so that the dampingmechanism converts the liner displacement of the screw portion into therotational motion of the rotational top.

The damping rod in accordance with the present invention comprises firstand second connective members so coupled with each other, and the firstconnective member further comprises a first rod formed with a guidescrew at least in its connecting side, a guide nut engaged with theguide screw and axially supported so as to rotate and slide on the guidescrew on the basis of a relative displacement from the guide screw, anda cylindrically shaped rotational body having a sufficiently largerdiameter than the first rod and having a sufficiently larger length inaxial direction than a diameter itself and further being rotatably andslidably attached thereto through the guide nut, whilst the secondconnective member further comprises a cylindrically shaped casing formedin its connecting side for accommodating the cylindrically shapedrotational body and the guide nut, wherein a viscous material and/or aviscoelastic material is filled for damping in a gap defined between aninner wall of the cylindrically shaped casing and the cylindricallyshaped rotational body.

A displacement conversion magnification (relative velocity increaserate) is more largely increased as compared to the conventional device.In accordance with the damping device of the present invention allowsthe simple and compact structure to achieve easily the large dampingeffect.

The above damping devices in accordance with the present invention aresimply and compactly structured exhibiting the sufficient dampingeffects as described in the damping top and the damping rod, for whichreason similarly to the damping top and the damping rod, the dampingdevice may be simply and compactly structured and exhibits thesufficient damping effect.

What is claimed is:
 1. A damping device comprising: first and secondconnective members so connected with each other as to be relativelydisplaceable; said first connective member further comprising a firstrod formed with a guide screw in its connecting side, a guide nutengaged with said guide screw and axially supported so as to rotate andslide on said guide screw on the basis of a relative displacement fromthe guide screw, and a disk-shaped rotational body having a sufficientlylarger diameter than said first rod and being rotatably and slidablyattached thereto through said guide nut; said second connective memberfurther comprising a second rod, and a cylindrically shaped casingformed in its connecting side for accommodating said rotational body andsaid guide nut, said damping device comprising at least one selectedfrom the group consisting of a viscous material and a viscoelasticmaterial is filled for damping in a gap defined between an inner wall ofsaid cylindrically shaped casing and said rotational body.
 2. Thedamping device as claimed in claim 1, wherein said rotational body is sounitary formed as to extend radially and outwardly from a circumferenceof said guide nut.
 3. The damping device as claimed in claim 1, whereinsaid rotational body is provided at a position distanced in an axialdirection from said guide nut and also is so formed as to be engagedwith one side of said guide nut.
 4. A method of using a damping device,wherein said damping device comprises first and second connectivemembers so connected with each other as to be relatively displaceable,said first connective member further comprising a first rod formed witha guide screw in its connecting side, a guide nut engaged with saidguide screw and axially supported so as to rotate and slide on saidguide screw on the basis of a relative displacement from the guidescrew, and a disk-shaped rotational body having a sufficiently largerdiameter than said first rod and being rotatably and slidably attachedthereto through said guide nut; said second connective member furthercomprising a second rod, and a cylindrically shaped casing formed in itsconnecting side for accommodating said rotational body and said guidenut, said damping device further comprising at least one selected fromthe group consisting of a viscous material and a viscoelastic materialis filled for damping a gap defined between an inner wall of saidcylindrically shaped casing and said rotational body, the methodcomprising: providing said damping device between at least one selectedfrom the group consisting of precast members and fair-facedconstructions in a fair-face building constriction including precasts ofconcrete, so that said damping device is allowed to be compressed andtensed.
 5. The method of claim 4, wherein said damping device isprovided between a precast column and a precast beam.
 6. The method ofclaim 4, wherein said damping device is provided between a precastcolumn and a fair-faced floor slab.
 7. The method of claim 4, whereinsaid damping device is provided within a fair-faced floor slab.
 8. Themethod of claim 4, wherein said damping device is provided between afoundation of a building construction and a fair-faced floor slab. 9.The method of claim 4, wherein said damping device is provided between afoundation and a vibration-isolating construction on said foundation, sothat said damping device is allowed to be compressed and tensed.
 10. Adamping device comprising: first and second connective members soconnected with each other as to be relatively displaceable; said firstconnective member further comprising an inner tube formed with a guidescrew in its connecting side, and a disk-shaped rotational body engagedwith said guide screw and having a sufficiently larger diameter thansaid inner tube and being attached thereto rotatably and slidably on thebasis of a relative displacement from the guide screw; said secondconnective member further comprising an outer tube, and a cylindricallyshaped casing formed in its connecting side for accommodating saidrotational body, said damping device, comprising at least one selectedfrom the group consisting of a viscous material and a viscoelasticmaterial is filled for damping in a gap defined between an inner wall ofsaid cylindrically shaped casing and said rotational body.
 11. Thedamping device as claimed in claim 10, wherein said rotational bodycomprises a disk-shaped body and a brimmed part being thinner than saiddisk-shaped body and extending radially and outwardly from acircumference of said disk-shaped body.
 12. A damping device comprising:first and second connective members so connected with each other as tobe relatively displaceable; said first connective member furthercomprising a first rod formed with a guide screw at least in itsconnecting side, a guide nut engaged with said guide screw and axiallysupported so as to rotate and slide on said guide screw on the basis ofa relative displacement from the guide screw, and a cylindrically shapedrotational body having a sufficiently larger diameter than said firstrod and having a sufficiently larger length in axial direction than adiameter itself and further being rotatably and slidably attachedthereto through said guide nut; said second connective member furthercomprising a cylindrically shaped casing formed in its connecting sidefor accommodating said cylindrically shaped rotational body and saidguide nut, said damping device comprising a viscous material and aviscoelastic material is filled for damping in a gap defined between aninner wall of said cylindrically shaped casing and said cylindricallyshaped rotational body.
 13. The damping device as claimed in claim 12,wherein said cylindrically shaped rotational body comprises a cylinderhaving one end into which said guide nut is inserted and an oppositeclosed end, wherein one side of said guide nut and said opposite closedend of said are rotatably and axially supported.
 14. The damping deviceas claimed in claim 12, wherein said cylindrically shaped rotationalbody comprises a tube-like rotational body having one end into whichsaid guide nut is inserted and an opposite opened end, wherein oppositesides of said guide nut are rotatably and axially supported and furthercomprising at least one selected from the group consisting of saidviscous material and said viscoelastic material is also filled into ahollow portion of said tube-like rotational body.
 15. A method of usinga damping device, wherein said damping device comprises first and secondconnective members so connected with each other as to be relativelydisplaceable; said first connective member further comprising a firstrod formed with a guide screw in its connecting side, a guide nutengaged with said guide screw and axially supported so as to rotate andslide on said guide screw on the basis of a relative displacement fromthe guide screw, and a disk-shaped rotational body having a sufficientlylarger diameter than said first rod and being rotatably and slidablyattached thereto through said guide nut; said second connective memberfurther comprising a second rod, and a cylindrically shaped casingformed in its connecting side for accommodating said rotational body andsaid guide nut, said damping device further comprising at least oneselected from the group consisting of a viscous material and aviscoelastic material is filled for damping a gap defined between aninner wall of said cylindrically shaped casing and said rotational body,the method comprising providing said damping device between diagonallyopposite comers of a frame structure in a building construction, so thatsaid damping device is allowed to be compressed and tensed.
 16. A methodof using a damping device, wherein said damping device comprises firstand second connective members so connected with each other as to berelatively displaceable; said first connective member further comprisinga first rod formed with a guide screw in its connecting side, a guidenut engaged with said guide screw and axially supported so as to rotateand slide on said guide screw on the basis of a relative displacementfrom the guide screw, and a disk-shaped rotational body having asufficiently larger diameter than said first rod and being rotatably andslidable attached thereto through said guide nit; said second connectivemember further comprising a second rod, and a cylindrically shapedcasing formed in its connecting side for accommodating said rotationalbody and said guide nut, said damping device further comprising at leastone selected from the group consisting of a viscous material and aviscoelastic material is filled for damping a gap defined between aninner wall of said cylindrically shaped casing and said rotational body,the method comprising: providing said damping device to connect deviceisolated floors through a precast steel building extending throughoutsaid isolated floors and also extending along an outermost verticalcolumn of said building which comprises a plurality of floors.
 17. Amethod for using a damping device, wherein said damping device.comprises first and second connective members so connected with eachother as to be relatively displaceable; said first connective memberfurther comprising an inner tube formed with a guide screw in itsconnecting side, and a disk-shaped rotational body engaged with saidguide screw and having a sufficiently larger diameter than said innertube and being attached thereto rotatably and slidably on the basis of arelative displacement from the guide screw; said second connectivemember further comprising an outer tube, and a cylindrically shapedcasing formed in its connecting side for accommodating said rotationalbody, said damping device further comprising at least one selected fromthe group consisting of a viscous material and a viscoelastic materialis filled for damping a gap defined between an inner wall of saidcylindrically shaped casing and said rotational body, the methodcomprising: providing said damping device to connect isolated floorsthrough a precast steel building extending throughout said isolatedfloors and also extending along an outermost vertical column of saidbuilding which comprises a plurality of floors.
 18. A method for using adamping device, wherein said damping device comprises first and secondconnective members so connected with each other as to be relativelydisplaceable; said first connective member further comprising a firstrod formed with a guide screw at least in its connecting side, a guidenut engaged with said guide screw and axially supported so as to rotateand slide on said guide screw on the basis of a relative displacementfrom the guide screw, and a cylindrically shaped rotational body havinga sufficiently larger diameter than said first rod and having asufficiently larger length in axial direction than a diameter itself andfurther being rotatably and slidably attached thereto through said guidenut; said connective member further comprising a cylindrically shapedcasing formed in its connecting side for accommodating saidcylindrically shaped rotational body and said guide nut, said dampingdevice further comprising at least one selected from the groupconsisting of a viscous material and a viscoelastic material is filledfor damping a gap defined between an inner wall of said cylindricallyshaped casing and said cylindrically shaped rotational body, the methodcomprising: providing said damping device between diagonally oppositecomers of a frame stricture in a building construction, so that saiddamping device is allowed to be compressed and tensed.
 19. A method forusing a damping device, wherein said damping device comprises first andsecond connective members so connected with each other as to berelatively displaceable; said first connective member further comprisinga first rod formed with a guide screw at least in its connecting side, aguide nut engaged with said guide screw and axially supported so as torotate and slide on said guide screw on the basis of a relativedisplacement from the guide screw, and a cylindrically shaped rotationalbody having a sufficiently larger diameter than said first rod andhaving a sufficiently larger length in axial direction than a diameteritself and further being rotatably and slidably attached thereto throughsaid guide nut, said connective member further comprising acylindrically shaped casing formed in its connecting side foraccommodating said cylindrically shaped rotational body and said guidenut, said damping device further comprising at least one selected fromthe group consisting of a viscous material and a viscoelastic materialis filled for damping a gap defined between an inner wall of saidcylindrically shaped casing and said cylindrically shaped rotationalbody, the method comprising: providing said damping device between afoundation and a vibration-isolating construction on said foundation, sothat said damping device is allowed to be compressed and tensed.